Award-Bait Song: At least one per album: "To One in Paradise", "Don't Let It Show" (from I, Robot), "Day After Day", "The Eagle Will Rise Again", "If I Could Change Your Mind", "Time", "Old and Wise", "I Wouldn't Want To Be Like You" (from I, Robot)...
"Sirius" is arguably the Crowning Music amongst NBA fans, due to its use by the Chicago Bulls as their player intro music. Even if you're not a Bulls fan, you do recognize the music. The song even spread to other NBA teams, the NFL, the NCAA and even the Italian soccer team U.S. Sassuolo Calcio.
Among fans, there seems to be general consensus that if Lenny Zakatek is singing on a track, it usually means the song in question is going to be good. Commonly cited evidence includes "I Wouldn't Want To Be Like You" (from I, Robot), "Games People Play" and "You Don't Believe".
Even some of their more obscure songs, such as "Can't Take it With You" and "La Sagrada Familia," are pretty epic.
As for non-guitar riffs, "I Robot", "Psychobabble", and "Standing On Higher Ground".
Face of the Band: Somewhat understandably, the Alan Parsons Project is often referred to as Alan Parsons's 'solo' career despite the equal contribution of singer/songwriter/keyboardist/bloke who came up with all the ideas for the concept albums Eric Woolfson. A fact somewhat underlined by all of the albums following Woolfson's departure being released under the sole name of Alan Parsons.
Genius Bonus: Or rather, Well-Traveled Bonus. The escalators in the cover art for I, Robot are those of Paris Charles DeGaulle Airport as it stood in the 1970s. (The escalators still exist, but you won't necessarily see them if you go through CDG; they're part of Terminal 1, which used to be the whole airport but is now something of a backwater, only operating flights for airlines not connected to Air France. It's rather a weird experience, whether or not you've seen the I Robot cover art.)
Harsher in Hindsight: The entire Eve album. While the band said that Eve was "an appreciation of the strengths and characteristics of women in general and the problems they face in the world of men" and was potentially meant to be sympathetic to women, it's essentially an album of Misogyny Songs, due to the perspective that it's sung from. The singles from the album basically said, "You're a slut" ("You Lie Down with Dogs", with the lyric finishing with, "you get up with fleas"), and "You emasculated me" ("Winding Me Up"); the opening song is even called "Lucifer". The album features the only female vocalists on an APP album: one sings a song about chasing one's dreams, but the other sings about dropping their newfound life if their man will take them back. Couple all of this with the album artwork, featuring women wearing veils with open sores on their faces, and it's certainly a package that hasn't aged well.
"Time", about the finitude of life and originally sang by Eric Woolfson, became this after he passed away in 2009. His former teammate Lenny Zakatek recorded a tribute cover.